Tii cold idle adjustment

[eurotrash]

I searched. Always do. 
Does anyone have any advice and tutorial type info on raising the cold start idle. 
I was delivered a recently restored ‘72 Tii that has the motor and kfish rebuilt, but was horribly out of adjustment. 
Having started at zero and gone through the entire set up procedures for the motor and injection system, I have it 98% where it should be, and already 100% better than it was when I got it. All cold and warm setting are confirmed, other than the verboten screw never really touching when hot (I haven’t touched that) 
The one thing, after getting all other issues and adjustments mostly sorted, is a very low cold start idle. Like, 500rpm ish.
 As I understand it, the air by-pass/cold idle speed adjustment is at the WUR. The large threaded bit on top. I just don’t know how to approach its adjustment. 
The cold start electronics were fubar from the get go, so I installed a CSV push button in the car. It’s starts easily, even on 30 degree mornings. Holds its low idle well, and comes up to 8-900 once warm. 
 

thanks all. I’m just looking for confirmation and advice on how to raise the cold start idle now. 

 

Merry Christmas! (Or, your respective holiday, this season 🤷🏻)

[jgerock]

I’m guessing the car doesn’t have a WB 02 sensor and gauge.

[Preyupy]

Can you see if the WUR is actually moving?  Look at the tip of the Verboten screw.  When it is cold it should be further away from the stop and touching the stop when it is warm.  If it is not moving, there is a good chance the WUR is not working and as such the "cold start air bypass" is probably not working as well.  

[dlacey]

8 hours ago, eurotrash said:

the air by-pass/cold idle speed adjustment is at the WUR. The large threaded bit on top.

I don't think that's adjustable...at least not on the majority of tii, it should just be tight against the collar below. On early cars where there's a locknut on that collar, you could (in principle) unscrew it a few turns and lock it with the nut. You can adjust the height the cone sits on the threaded rod.. that's part of the setup of the WUR to set the height of that cone on the road at a specific temperature.... Maybe that's been altered??

When cold, is the "cone" part low down inside the collar?? That's maximum "fast idle" air flow... If the cone sits higher when cold then maybe the cone is set too high on the threaded rod? Or your WUR is mechanically jammed?

Edited December 23, 2023 by dlacey

[eurotrash]

This makes sense. I must have misunderstood when I was studying the parts and mistook what they were referring to.  

And the car is a ‘72..  while the cone travel is to the 10mm above when warm. Cold, it does seem to sit a bit higher than others I have seen. I will look closer and try to see about setting the cone deeper when cold. It may explain or sort out some of the other tuning question marks I have noticed. 
 

Thank you. 

Edited December 26, 2023 by eurotrash

[eurotrash]

On 12/22/2023 at 5:07 PM, jgerock said:

I’m guessing the car doesn’t have a WB 02 sensor and gauge.

It does not. 

[eurotrash]

This is how the WUR looked when the car was brought to me. Cold and hot. Rich as L on warm up. 
 

The third photo is again cold, after I had begun to make the proper base line adjustments per the tuning guide. The cone sits proud as compared to other photos I have been shown or found in searching. It appears to need adjusted down, if I am understanding the function correctly. 

[dlacey]

It looks like it needs to be re-set, seems the actuator is working OK, just needs calibration.. The centre picture, "full temp', shows the top hat washer still in contact with the enrichment arm,  if the verboten screw is not hitting it's stop under these conditions then your full throttle mixture may be too rich. In the last pic, the height of the cone looks as it should be at 30C/86F... dunno what temp you were actually at when that pic was taken. The WUR calibration procedure is in this article:

 

[eurotrash]

The last photo is the car cold after I went through the set up process, probably 50F. Not sure exactly, but definitely colder than 86F degrees. That’s as deep as the cone will travel, and the reason for the post to begin with. I can’t find any details on how to adjust it.
I went through the entire set up procedure to get it to the place it is today. And what I have is a pretty strong runner with:

A low cold start idle. 
The cone sits proud when cold. 

The verboten screw stops just short of touching its stop when hot. 
 

..which led me to wondering if they are somehow related problems and searching g for the illustrated procedure on how to adjust the cold idle speed. 

Edited December 27, 2023 by eurotrash

[eurotrash]

In re-reading the calibration steps, I would prefer to not have to remove the WUR if possible. I have to imagine that the steps I would have to take to perform this in-car would be as follows:

1. Warm up the car to expose the grub.

2. Secure the threaded rod.

3. Turn the cone a full turn down the threaded rod, at least, and reset the grub. 
4. Let cool and test for cold idle speed. 
5. Rinse and repeat, as needed. 
 

Please correct me if I am wrong. 

Edited December 27, 2023 by eurotrash

[dlacey]

46 minutes ago, eurotrash said:

I have to imagine that the steps I would have to take to perform this in-car would be as follows:

Yes, you can do it that way, if the grub screw is not rotated in a way to be accessible, you can use the 2 flats on the top of the threaded rod to rotate the rod & cone until the grub screw is in view.

[eurotrash]

Excellent. I am doing this tomorrow. The owner is coming to see the car after several weeks of (part time) work. Hopefully a 1200 rpm cold start idle is in our future.
Thanks, and I will report back with photos for later searchers. 

[eurotrash]

This is what I have with the cone height, before making any changes. . Not sure I want to curse this much today. I might not touch it. 
but I really need that cold start idle to come up. Ugh. 
Maybe I will revisit timing first. He has a lightweight fly wheel in car and I has no pressed-in ball. So that’s fun too. 
 

 

Edited December 29, 2023 by eurotrash

['76mintgrün'02]

3 minutes ago, eurotrash said:

Maybe I will revisit timing first. He has a lightweight fly wheel in car and I has no pressed-in ball. So that’s fun too. 

 

Hopefully, you have a variable advance timing light, such as the Innova 5568 (my personal favorite = money well spent)

 

 

[JsnPpp]

Consider doing a highly manual test. Loosen the "top hat" so that it allows full range of motion on the WUR link, or remove the lock nut to allow rapid adjustment. Start the car cold and then manually move the WUR linkage up or down and see if you can find the ideal idle speed. If so, lock it there and then try again once cool. It shouldn't be too hard to get in there with cold engine, you won't burn your hands. 

 

Also keep in mind that the WUR do get a bit worn. I had two where one let a lot more air through when it was "closed" than the other. It's workable, you may just need to compensate it elsewhere.

 

Sounds like you are making progress!